Approximately 100 different species are currently farmed in aquaculture operations around the world. Canadian aquaculturists farm various species of finfish, shellfish, and aquatic plants.
Approximately 100 different species are currently farmed in aquaculture operations around the world. Canadian aquaculturists farm various species of finfish, shellfish, and aquatic plants.
Salmon are fed nutrient-dense, dry pellets consisting of natural products. Using ingredients that are tested for quality and purity, feed manufacturers tailor-make feeds to suit the exact dietary requirements of the salmon at each stage of their life cycle. Currently, the main ingredients are fish meal, fish oil and plant proteins (such as soy). The fish meal and oil are primarily made from forage fish that are too small and bony to be used for human consumption.
Canadian feed manufacturers are developing new feeds that are increasingly replacing some of the fish-based ingredients in salmon feed with ingredients from sustainable sources such as vegetables – yet still provide high quality, nutritious farmed salmon. In some salmon feeds, the use of alternative ingredients has allowed a 50% reduction in the use of fish meal and fish oil - with no significant reduction in the amount of heart-healthy omega-3 fatty acids in the fish. As a result, Canadian salmon farmers now use less than 30% fish meal and oil in their feed. That means only 0.4 kg of wild fish meal and oil are needed to grow 1 kg of farmed salmon. Where possible, the alternative feed ingredients are sourced locally.
Farmed salmon convert feed into their muscles, fat and bones very efficiently. While a cow needs about 7 kg of feed for every kg of weight that it gains, new studies show that farmed salmon need only about 1 kg of feed for every kg of weight gained.
Sea lice are naturally occurring parasites that feed on the skin and mucous of both wild and farmed salmon. Sea lice cannot live in fresh water – therefore all smolts are free of sea lice before they enter the net pens. However, since sea lice are able to pass through the netting of the pens, farmed salmon may become infected by the sea lice carried by wild salmon in the surrounding water. Since this parasite cannot be eliminated from wild salmon, salmon farmers have developed management practices that reduce the likelihood of infection.
The effectiveness of these management practices is supported by many scientific studies that suggest that salmon farms have little impact on the sea lice levels that naturally occur on wild salmon. For example:
Life cycle analysis (LCA) demonstrates that farmed salmon perform better than other food proteins in terms of key environmental impact measures:
Energy Use: the evidence indicates that the life-cycle energy intensity for farm-raised salmon is better than beef.
All salmon farming companies in Canada are certified to one or more third-party certification program that assures consumers that they are purchasing high quality, sustainably produced salmon.
While Ontario is the largest trout producer in Canada, trout farms can be found in all ten Canadian provinces. In 2013, Canadian trout farmers produced 6,700 tonnes of high quality trout valued at about $39 million.
Farmed trout are fed nutrient – dense digestible feed pellets which the fish convert efficiently. While fish meal remains a component of trout feeds, great efforts have been made to lower the reliance upon fish meal by substituting other protein sources such as soybean and corn meal. In fact, in the past decade, the percentage of fish meal used in trout feeds has decreased by about 50% as a result of the use of these alternate protein ingredients. Reliance upon fish meal has also been decreased through improvements in the feed conversion efficiency of trout.
Arctic char (Salvelinus alpinus) is a member of the Salmonid family – and resembles a salmon in appearance. Arctic char have a coral colored flesh with a taste somewhat milder than Atlantic salmon.
Canadian Arctic char are farmed in the Yukon Territory, Nova Scotia, and New Brunswick, Quebec and Manitoba.
Arctic char are raised in land-based systems. Arctic char eggs are hatched within specialized hatchery facilities. The young fish remain in the hatchery until they reach ~100 grams; the fish are then transferred to tanks at the grow-out facilities. Each of these tanks is capable of holding 5000 fish. While they take almost a year to reach 100 grams, Arctic char exhibit a rapid growth spurt during the grow-out phase – reaching market weight (1-2.5kg) within the next 12 months.
Arctic char are fed nutrient-dense, dry pellets. Using ingredients that are tested for quality and purity, feed manufacturers tailor make feeds to suit the exact dietary requirements of the fish at each stage of their life cycle. Currently, the main ingredients are fish meal and fish oil. The fish meal and oil are primarily made from forage fish that are too small and bony to be used for human consumption. Feed manufacturers are developing new feeds that will replace some of the fish-based ingredients with sustainable ingredients from other sources such as vegetables – yet still provide high quality, nutritious farmed Arctic char.
Feed manufacturers also add essential vitamins, minerals and carotenoids to Arctic char feed. Carotenoids are important antioxidants that help to ensure the optimal health of the fish. Carotenoids also give Arctic char its characteristic coral coloration.
The land-based Arctic char rearing systems are considered to be among the most environmentally responsible fish farming designs. Features of the most systems include removal of particulate matter and effluent prior to releasing water from the fish tanks into the environment. Waste sludge removed from the water is then provided to terrestrial farmers for use on crops – while leftovers from fish processing may be incorporated into dog food or delivered to local compost facilities.
Arctic Char is highlighted as a “Best” choice by the Monterey Aquarium Seafood Watch Guide for Healthy Oceans.
In winter, wild Arctic char gather close together in small pockets of unfrozen fresh water – they are therefore accustomed to living in very close quarters with one another. As a result, farmed Arctic char must also be stocked at high densities in the rearing tanks; when stocked at low densities, the char grow poorly and have a higher incidence of illness.
Sablefish (Anopoploma fimbria) – also known as Blackcod – is a deep-water fish that is quite widely distributed along the continental shelf of the Northern Pacific Ocean ranging from California north to Alaska and the Bering Sea.
All approvals for sablefish farms in Canada are subject to an intensive environmental review according to both federal and provincial legislation. Sablefish farms can only be sited in areas where water currents provide optimal conditions for fish health and environmental sustainability.
In addition to ensuring that their farms are sustainable, sablefish farmers are also helping to ensure the sustainability of wild sablefish populations. As a result of sustained over fishing, the standing stock biomass of the wild sablefish has fallen by approximately 100,000 metric tons over the last 10 years. As farmed sablefish production increases, it will supply an increasing proportion of the consumer demand for sablefish – thereby decreasing the pressure on wild populations created by the wild fishery.
Sablefish are fed nutrient-dense, dry pellets made of fish meal, fish oil and wheat. No pigmentation is added to the fish feed to adjust flesh color. The fish meal and oil are primarily made from herring by-catch or anchovies. The feed manufacturer also adds essential vitamins, and minerals to feed.
Tilapia is a warm water, fresh water fish farmed in a few locations in Canada. The flesh is white, moist and mild-flavoured – making it a versatile choice for a variety of recipes. While dozens of species are farmed worldwide, three species make up the bulk of production. The main species farmed in Canada is the Nile tilapia, Oreochromis niloticus.
Tilapia is one of the fastest growing fish farming sectors globally, led by China and other low cost Asian and South American producers. Over 4 million tonnes were produced in 2012, and it is now in the top 10 fish species consumed in North America.
All of the Canadian production is sold live to local markets, where premium prices are obtained for fresh, live fish. Toronto is the single largest market for live tilapia in North America - while burgeoning markets exist in Calgary, Edmonton, and Vancouver.
Tilapia are raised in land-based, heated tank systems that employ state-of-the-art recirculation technology. The same water is reused several times by the fish. The waste water is then treated with biological nutrient removal processes including aquaponics – systems combining hydroponic plant production with fish farming – to enhance the overall value of production. High end Boston lettuce and herbs are produced in aquaponics in Canada.
Tilapia require temperatures above 24 C in order to thrive. Their fast growth means the fish reach maturity at only a few months of age. Farmed tilapia can therefore produce several broods each year(unlike our cold-water species which typically only produce one brood per year). Tilapia are stocked in tanks at very small fingerling sizes (< 2 grams) supplied from Canadian hatchery breeding stock. While 200-400 gram tilapia are preferred for the live markets, they can grow to 45 cm in size and up to 2 kg in weight,. Growth from fingerling to market size typically takes less than 10 months in land-based rearing systems.
Tilapia are omnivorous, eating a variety of plant and animal products. Commercial diets consist mostly of lower cost plant-protein ingredients. Work is underway to more effectively utilize cereal and grain crops grown in the Canadian prairie provinces for use in tilapia diets both in Canada and globally.
Tilapia utilize plant-based diets produced primarily from low impact agricultural commodities.
Tilapia are raised in closed containment systems on land. Tilapia production requires minimal access to water as the fish can be reared in high densities in land-based systems with relatively little water turnover. The systems employed for culture are self-cleaning and generate little in the way of organic and inorganic waste. These systems generate in extremely low to nil environmental impacts on the surrounding environment.
Tilapia is sometimes referred to as St. Peter’s fish, as they are believed to be the fish caught when Christ asked St. Peter to cast out his net in the Sea of Galilee.
It is believed the Egyptians farmed tilapia for food over 3,000 years ago.
Atlantic halibut (Hippoglossus hippoglossus) is a marine, cold-water flat fish that is currently being developed as a commercial aquaculture species. Halibut is a white-fleshed fish with high market value and demand; it is therefore an excellent species to complement and diversify the Canadian aquaculture industry.
To produce the highest quality farmed halibut, the very best adult female fish are selected each year as breeding stock. Halibut broodstock are maintained in onshore tanks. Each female produces several batches of eggs each season; in a single season, a female can produce well over 100,000 eggs per kg of body weight. These eggs are fertilized and incubated in the temperature-controlled tanks in a seawater hatchery.
Fertilized eggs hatch approximately 15 days after fertilization. Upon hatching, the halibut larvae are transferred to the ‘larval’ tanks. The newly hatched larvae are only 6 or 7 mm in length – barely recognizable as fish. During their first 50 days of life, the larvae receive nourishment from their yolk-sac. As the yolk sac is depleted, halibut farmers begin to feed the larvae a variety of small planktonic animals. This diet of plankton is gradually replaced with a high quality pelleted feed designed specifically for halibut larvae.
After approximately 50 days, the halibut larvae undergo a metamorphosis during which both eyes migrate to one side and they display the flattened appearance of adult fish. The young halibut are kept in circular tanks at the hatchery until they reach ~5 grams. The hatchery phase generally takes 6-7 months. Following this, they undergo a nursery phase until they reach a size of 100-200 grams and are ready for deployment in sea cages.
Halibut are fed pelleted feeds containing high quality ingredients such as fish oils, meals, vitamins and minerals that ensure an excellent feeding response and good growth. During the on-growing phase, halibut require only 1 to 1.5 kg of feed for every kg of weight gained.
Why they’re environmentally sustainable…
All approvals for halibut farms in Canada are subject to an intensive environmental review according to both federal and provincial legislation, including the Canadian Environmental Assessment Act (CEAA). Halibut farms can only be sited in areas where water currents provide optimal conditions for fish health and environmental sustainability.
An adult broodstock Atlantic halibut weighs between 50 and 125 kgs - larger than most humans. They are very powerful and one flick of the tail of a broodstock halibut can easily break a human arm or leg.
The shelf-life of fresh, head-on gutted halibut is up to three weeks on ice, much longer than most fish. The protective mucous on the fish’s skin contains hyppicin, a naturally occurring compound produced by the halibut that prevents bacterial development and reduces spoilage after harvest.
A number of alternate, newer species are under development and commercialization in Canada. The purpose is to diversify production, enhance natural capture fisheries production, and access new market opportunities for the increasing global demand for healthy, high quality seafoods.
The roe (eggs) of green sea urchins (Strongylocentrotus droebachiensis) and red sea urchin (S. franciscanus) are an expensive delicacy in Japan, parts of Europe, and increasingly in South and North America. Because the demand for sea urchin roe – called “uni” in sushi bars – has grown dramatically over the past decade, many traditional fisheries have been virtually depleted of sea urchins. The development of sea urchin aquaculture could create a new multi-million dollar industry in Canada – as well as contribute to the rehabilitation of wild sea urchin populations in areas depleted due to overfishing.
Due to its ability to thrive in cold marine waters, spotted and Atlantic wolffish are considered very promising candidate species for cold water aquaculture in the North Atlantic. Wolffish also display remarkable attributes for domestication (tolerance to density, salinity, water quality changes, egg and larval size, no live prey requirements, and farming-friendly behavior) and market potential (excellent flesh and taste characteristics, niche market, price). Research efforts in Canada are aimed at developing domestic wolffish broodstocks and improving the survival of young wolffish.
Spotted and Atlantic wolffish are listed as “threatened” in nature due to overharvesting, and no commercial harvesting is permitted. The development of farming methods for wolffish will aid conservation efforts of wild wolffish by providing much needed insight into biological factors affecting natural populations. Farmed juvenile wolfish may also play an important role in wild wolffish enhancement efforts.
In Nova Scotia, Irish moss (Chondrus crispus) is farmed in land-based tanks for the edible Asian sea-vegetable market.
Food grade kelps are being co-cultivated in experimental farms for Integrated-Multi-Trophic Aquaculture, with the view of enhancing the sustainability of fed aquaculture systems and adding value to the overall process. Kelps can be used in a variety of traditional and novel dishes, and are an excellent source of iodine.
Northern or Pinto abalone (Haliotis kamtschatkana) are native to British Columbia’s coast. Due to the significance of abalone as a traditional food, many BC First Nations have expressed support for the development of a BC abalone aquaculture industry.
In Nova Scotia, red abalone (Haliotis rufescens) are currently being raised from small juveniles purchased from a hatchery in Iceland.
Abalone flesh is creamy white, firm in texture, and has a mild flavour. It is considered a gourmet delicacy in Japanese and Chinese cuisine. Since global market demand for abalone exceeds the market supply, abalone is a highly valuable commodity (CAD$30-40/kg).
Sea cucumbers (Parastichopus californianus) are an Asian delicacy with reported aphrodisiac qualities. Products from sea cucumber include muscle strips (fresh or frozen) and dried skins or sections. The main market for sea cucumber products is China and Japan. Sea cucumbers are co-cultured with fish and shrimp in Asia as a means of recycling nutrients and adding value to the production systems. Interest in developing sea cucumber culture in tandem with fish culture is now being evaluated in Canada as a means of enhancing the overall output of the systems.
Cockles (Clinocardium nuttalli) – also called basket cockles – are native to British Columbia’s coast. Due to significance of cockles as a traditional food, many BC First Nations have expressed support for the development of a BC cockle aquaculture industry.
Since the hardiness of cockles allows them to withstand severe winter conditions, they represent the best opportunity for intertidal bivalve culture on BC’s north coast. Market research indicates that cockles would be readily accepted into the upscale food service trade and sushi market.
In Eastern Canada, the primary mussel species farmed is the Blue mussel (Mytilus edulis). In British Columbia, both Blue mussels and Mediterranean mussels (Mytilus galloprovincialis) are farmed.
Eastern Canada (Prince Edward Island, Nova Scotia, New Brunswick, Newfoundland, Quebec) is Canada’s major mussel farming region: Prince Edward Island alone produced 76% of Canadian mussels in 2013. On the Pacific coast, the British Columbia mussel industry is growing – but remains small relative to Eastern Canada.
The production cycle on a Canadian mussel farm begins with the collection/production of mussel seed. In Atlantic Canada, seed are usually collected in the wild. In British Columbia, all mussel seed come from hatchery broodstock.
Once the seed begin to develop into mature mussels, they are placed into lengths of mesh sleeves called socks. The socks are then attached to a rope that is suspended from an anchored buoy in deep subtidal water; the mesh of the sock ensures that the mussels have access to nutrient-rich seawater. The mussels remain within the sock until they reach market size – which takes 18 months to 3 years.
Mussels are filter feeders: they obtain all their required nutrients by drawing sea water through their gills and filtering out naturally occurring tiny plants and animals called plankton. Mussel farmers therefore do not need to feed their stock.
Mussel farming is, by definition, green and sustainable. Mussels cannot tolerate the discharge of sewage or other toxins; the presence of mussel farming, therefore, often results in increased awareness and monitoring of coastal waters. In addition to being important modulators of nutrient cycles in ecological systems, farmed mussels help to reduce greenhouse gases by removing carbon dioxide from the ocean for shell formation. Mussel farming is endorsed by environmental groups such as the Audubon Society, Monterey Bay Aquarium’s Seafood Watch and Eco-Fish.
Farmed shellfish improve water quality by filtering microscopic particles from the water. One kg of live mussels can remove up to 12g of nitrogen, 0.8g of phosphorous, and 50g of carbon.
Many shellfish farming companies in Canada are certified to one or more third-party certification program that assures consumers that they are purchasing high quality, sustainably produced shellfish
In New Brunswick, Prince Edward Island and Nova Scotia, the primary oyster species farmed is the American oyster (Crassostrea virginica)– also known as the Atlantic, Malpeque or Eastern oyster. In British Columbia, the primary farmed species is the Pacific oyster (Crassostrea gigas).
Canadian oyster production is distinctly divided between two regions: in 2013, 56% of the volume of Canada’s oysters was produced in BC; the remainder was produced in Atlantic Canada.
The production cycle on a Canadian oyster farm begins with the collection/production of oyster larvae. In both Atlantic and Pacific Canada, some farmers collect the larvae in the wild. However, larvae are increasingly produced in controlled hatchery facilities from spawning adult broodstock. The larvae are kept suspended in tanks by circulating water – and in a few weeks they transform into tiny seed. The seed is essentially a very small version of the adult oyster.
Once the seed reaches an appropriate size, it can be transferred to the ocean for final grow-out. However – in British Columbia – before final grow-out the oyster seed is often transferred to a ‘floating upwelling system’ (referred to as a ‘flupsy’) that is housed on a raft on the ocean. The seed are kept in compartments on the flupsy whereby nutrient rich ocean water is circulated – thereby allowing them to reach a larger size before the final grow-out phase.
When the seed is ready for the grow-out phase, it is transferred to the ocean where it may be reared in one of a variety of systems:
Shellfish farming requires no input other than providing a clean environment and limiting predation. Oysters are filter feeders: they obtain all their required nutrients by drawing sea water through their gills and filtering out naturally occurring tiny plants and animals called plankton. Oyster farmers therefore do not need to feed their stock, and rely solely on natural food supplies.
Oyster farming is, by definition, green and sustainable. Oysters cannot tolerate the discharge of sewage or other toxins; the presence of oyster farming, therefore, often results in increased awareness and monitoring of coastal waters.
In addition to being important modulators of nutrient cycles in ecological systems, farmed oysters help to reduce greenhouse gases by removing carbon dioxide from the ocean for shell formation.
Oyster farming is endorsed by environmental groups such as the Audubon Society, Monterey Bay Aquarium’s Seafood Watch and Eco-Fish.
Farmed shellfish improve water quality by filtering microscopic particles from the water. A single oyster can clear over 50 litres a day, retaining particles as small as 2 microns – even a small oyster farm can clean more than 350 million litres each day, reducing turbidity, increasing light penetration, improving water quality, and reducing anoxia (low oxygen).
Many shellfish farming companies in Canada are certified to one or more third-party certification program that assures consumers that they are purchasing high quality, sustainably produced shellfish.
Oysters are said to have aphrodisiac qualities. Some have related this phenomenon to the excellent nutrient content of oysters – especially vitamin E and zinc. Others say the aphrodisiac qualities are due to the dopamine content of oysters. Dopamine is a vital element that governs brain activity and influences sexual desire.
The first bottom leases for oyster farmers were actually provided to Nova Scotia and PEI farmers prior to confederation in the 1860's.
The Manila clam (Ruditapes phillippinarum) is the primary clam species farmed in Canada. Other clam species farmed include: Softshell clams (Mya arenaria), hard clams or quahaugs (Mercenaria mercenaria), Savory or Varnish clams (Nuttallia obscurata) and Geoducks (Panope abrupta).
The production cycle on a Canadian clam farm begins with the collection/production of clam larvae and juveniles. All clam larvae are produced in a hatchery from spawning adult broodstock. The larvae are kept in hatchery tanks where they transform into tiny juvenile clams (seed) within a few weeks. The seed is essentially a very small version of the adult clam. On the east coast, juvenile clams are collected in natural nursery areas using various collector substrates.
After leaving the hatchery, the young clams are transferred to nursery facilities to allow them to reach a larger size. One type of nursery system that is commonly used in British Columbia is a ‘floating upwelling system’ (referred to as a ‘flupsy’) that is housed on a raft on the ocean. The seed are kept in compartments on the flupsy where nutrient rich ocean water is circulated – thereby allowing them to reach a larger size before the final grow-out phase.
Once the nursery phase is completed, the juvenile clams are carefully spread on subtidal regions of an ocean beach where they then burrow into the substrate. Clams remain on the beach for 2 to 4 years – until they reach marketable size. Clams are usually harvested by hand using a long tined rake. Yields of clams on well-managed farm plots can reach to over 2kg per square meter each year.
Clams are both filter feeders and deposit feeders: they obtain all their required nutrients by drawing sea water through their gills and filtering out naturally occurring tiny plants and animals called plankton, as well as organic material on the seabed. Clam farmers therefore do not need to feed their stock, and rely solely on natural food supplies for production.
Clam farming is, by definition, green and sustainable. Clams cannot tolerate the discharge of sewage or other toxins; the presence of clam farming, therefore, often results in increased awareness and monitoring of coastal waters for pollution control.
In addition to being important modulators of nutrient cycles in ecological systems, farmed clams help to reduce greenhouse gases by removing carbon dioxide from the ocean for shell formation.
Clam farming is endorsed by environmental groups such as the Audubon Society, Monterey Bay Aquarium’s Seafood Watch and Eco-Fish.
Aside from their food value, clams are efficient accumulators of environmental contaminants such as heavy metals and have been used in some areas for habitat remediation from industrial pollution.
Clams are excellent sources of protein and calcium, are rich in minerals such as iron and zinc, and contain good levels of vitamin B. They also contain high levels of natural DHA omega-3 fatty acids that are essential for human functions and important in reducing the risk of heart disease and other human diseases.
In British Columbia, the primary species of scallop farmed is a Japanese/weathervane hybrid scallop (Patinopecten caurinus x yessoensis) known as the Pacific or Qualicum scallop. In Eastern Canada, the giant or sea scallop (Placopecten magellanicus) and the Northern Bay Scallop (Argopecten irradians irradians) are the primary species farmed.
Where they’re farmed…
Canadian production of farmed scallops occurs in British Columbia, Nova Scotia, New Brunswick, and Quebec. In 2013, British Columbia produced 85% of Canada’s farmed scallops.
The production cycle on a Canadian scallop farm begins with the collection/production of scallop larvae. On Canada’s Atlantic coast, larvae are collected from adults spawning in the wild – as well as from hatchery broodstock. In British Columbia, all scallop larvae come from hatchery broodstock.
As the larvae settle and become juvenile scallops, they begin to develop into mature scallops; they are transferred to a fine mesh bag or tray – which is then attached to a secured flotation device and suspended in the ocean.
When the scallops are large enough to begin the final grow-out phase of production, some Canadian farmers ‘seed’ the scallops on the ocean floor (bottom culture). Other farmers transfer their scallops to larger mesh bags or trays – and re-suspend them from secured flotation devices (suspension culture). Scallops grown in suspension systems take six months to three years to reach market size depending on the final product – whereas bottom grown scallops require a further two to three years.
Scallops are filter feeders: they obtain all their required nutrients by drawing sea water through their gills and filtering out naturally occurring tiny plants and animals called plankton. Scallop farmers ensure that the mesh size of the scallop rearing bags is large enough to ensure good flow-through of nutrient rich sea water. As a result, scallop farmers do not need to feed their stock. They rely solely on the provision of high quality, natural food from the environment.
Scallop farming is, by definition, green and sustainable. Scallops cannot tolerate the discharge of sewage or other toxins; the presence of scallop farming, therefore, often results in increased awareness and monitoring of coastal waters.
In addition to being important modulators of nutrient cycles in ecological systems, farmed scallops help to reduce greenhouse gases by removing carbon dioxide from the ocean for shell formation.
Scallop farming is endorsed by environmental groups such as the Audubon Society, Monterey Bay Aquarium’s Seafood Watch and Eco-Fish.
Scallops have the ability to “swim” short distances by rapidly snapping their shells. This ability develops an oversized muscle referred to as the adductor, the main edible portion of the scallop.
IMTA is still in the developmental stages. In a pilot project in the Bay of Fundy, New Brunswick, Canadian researchers investigated the benefits of rearing Blue mussels and kelps near pre-established Atlantic salmon aquaculture sites. In this system, any feed not eaten by the salmon – together with other organic wastes – is then available as a nutrient source for the mussels.
As part of their natural metabolic processes, both the salmon and the mussels release soluble ammonia and phosphorus – thereby also providing essential nutrients for the kelps. This nutrient abundance is having a positive impact on the growth of both species: the mussels reach market size 8-10 months earlier than normal – and the kelps grow 46% more.
The mussels produced by the IMTA system would be ideal for the restaurant and retail trade – while markets for kelps include food, nutraceuticals, and other applications.